1 /* 2 * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.nio.ch; 27 28 import java.io.FileDescriptor; 29 import java.io.IOException; 30 import jdk.internal.access.SharedSecrets; 31 import jdk.internal.access.JavaIOFileDescriptorAccess; 32 import sun.security.action.GetPropertyAction; 33 import java.io.File; 34 import java.nio.CharBuffer; 35 36 class FileDispatcherImpl extends FileDispatcher { 37 38 private static final JavaIOFileDescriptorAccess fdAccess = 39 SharedSecrets.getJavaIOFileDescriptorAccess(); 40 41 // set to true if fast file transmission (TransmitFile) is enabled 42 private static final boolean fastFileTransfer; 43 44 FileDispatcherImpl() { } 45 46 @Override 47 boolean needsPositionLock() { 48 return true; 49 } 50 51 int read(FileDescriptor fd, long address, int len) 52 throws IOException 53 { 54 return read0(fd, address, len); 55 } 56 57 int pread(FileDescriptor fd, long address, int len, long position) 58 throws IOException 59 { 60 return pread0(fd, address, len, position); 61 } 62 63 long readv(FileDescriptor fd, long address, int len) throws IOException { 64 return readv0(fd, address, len); 65 } 66 67 int write(FileDescriptor fd, long address, int len) throws IOException { 68 return write0(fd, address, len, fdAccess.getAppend(fd)); 69 } 70 71 int pwrite(FileDescriptor fd, long address, int len, long position) 72 throws IOException 73 { 74 return pwrite0(fd, address, len, position); 75 } 76 77 long writev(FileDescriptor fd, long address, int len) throws IOException { 78 return writev0(fd, address, len, fdAccess.getAppend(fd)); 79 } 80 81 long seek(FileDescriptor fd, long offset) throws IOException { 82 return seek0(fd, offset); 83 } 84 85 int force(FileDescriptor fd, boolean metaData) throws IOException { 86 return force0(fd, metaData); 87 } 88 89 int truncate(FileDescriptor fd, long size) throws IOException { 90 return truncate0(fd, size); 91 } 92 93 long size(FileDescriptor fd) throws IOException { 94 return size0(fd); 95 } 96 97 int lock(FileDescriptor fd, boolean blocking, long pos, long size, 98 boolean shared) throws IOException 99 { 100 return lock0(fd, blocking, pos, size, shared); 101 } 102 103 void release(FileDescriptor fd, long pos, long size) throws IOException { 104 release0(fd, pos, size); 105 } 106 107 void close(FileDescriptor fd) throws IOException { 108 fdAccess.close(fd); 109 } 110 111 FileDescriptor duplicateForMapping(FileDescriptor fd) throws IOException { 112 // on Windows we need to keep a handle to the file 113 FileDescriptor result = new FileDescriptor(); 114 long handle = duplicateHandle(fdAccess.getHandle(fd)); 115 fdAccess.setHandle(result, handle); 116 fdAccess.registerCleanup(result); 117 return result; 118 } 119 120 boolean canTransferToDirectly(java.nio.channels.SelectableChannel sc) { 121 return fastFileTransfer && sc.isBlocking(); 122 } 123 124 boolean transferToDirectlyNeedsPositionLock() { 125 return true; 126 } 127 128 int setDirectIO(FileDescriptor fd, String path) { 129 int result = -1; 130 String filePath = path.substring(0, path.lastIndexOf(File.separator)); 131 CharBuffer buffer = CharBuffer.allocate(filePath.length()); 132 buffer.put(filePath); 133 try { 134 result = setDirect0(fd, buffer); 135 } catch (IOException e) { 136 throw new UnsupportedOperationException 137 ("Error setting up DirectIO", e); 138 } 139 return result; 140 } 141 142 static boolean isFastFileTransferRequested() { 143 String fileTransferProp = GetPropertyAction 144 .privilegedGetProperty("jdk.nio.enableFastFileTransfer", "false"); 145 return fileTransferProp.isEmpty() ? true : Boolean.parseBoolean(fileTransferProp); 146 } 147 148 static { 149 IOUtil.load(); 150 fastFileTransfer = isFastFileTransferRequested(); 151 } 152 153 //-- Native methods 154 155 static native int read0(FileDescriptor fd, long address, int len) 156 throws IOException; 157 158 static native int pread0(FileDescriptor fd, long address, int len, 159 long position) throws IOException; 160 161 static native long readv0(FileDescriptor fd, long address, int len) 162 throws IOException; 163 164 static native int write0(FileDescriptor fd, long address, int len, boolean append) 165 throws IOException; 166 167 static native int pwrite0(FileDescriptor fd, long address, int len, 168 long position) throws IOException; 169 170 static native long writev0(FileDescriptor fd, long address, int len, boolean append) 171 throws IOException; 172 173 static native long seek0(FileDescriptor fd, long offset) throws IOException; 174 175 static native int force0(FileDescriptor fd, boolean metaData) 176 throws IOException; 177 178 static native int truncate0(FileDescriptor fd, long size) 179 throws IOException; 180 181 static native long size0(FileDescriptor fd) throws IOException; 182 183 static native int lock0(FileDescriptor fd, boolean blocking, long pos, 184 long size, boolean shared) throws IOException; 185 186 static native void release0(FileDescriptor fd, long pos, long size) 187 throws IOException; 188 189 static native void close0(FileDescriptor fd) throws IOException; 190 191 static native long duplicateHandle(long fd) throws IOException; 192 193 static native int setDirect0(FileDescriptor fd, CharBuffer buffer) throws IOException; 194 }